Consumer products with wearable sensor technologies have enabled daily monitoring of biological data (e.g., heart rate, physical activity, and skin temperature) at relatively low cost. These products have shown the potential for contributing a positive impact on health outcomes for many groups of people, such as athletes, veterans, and the elderly. However, quantitative and qualitative assessment of the health impact of social interaction has mostly relied on self-reported data or external observation, which can yield limited accuracy and validity.